This invention relates to seals and more particularly to heavy duty seals for use with truck wheels, semi-trailer wheels and the like.
Typical heavy duty truck wheels and axle spindle assemblies are shown in Stephens, U.S. Pat. No. 3,064,982 issued Nov. 20, 1962 and Isenbarger, U.S. Pat. No. 3,177,041 issued Apr. 6, 1965. In each of these prior patents a wheel hub and spindle are shown in which the hub is adapted to contain a quantity of relatively light lubricating oil. The level of the lubricating oil may be observed by looking through a window formed in the hub cap. In each instance a single seal assembly between the hub and axle assembly is employed for retaining the lubricating oil liquid within the hub and for excluding dust, dirt and the like. From time to time it is necessary to remove the wheel from the axle for the purpose of inspecting or replacing the brakes, working on the anti-skid system, replacing the bearings or the like. The seals which are commonly employed have a metal-to-metal press fit on their inside and outside diameter, and the perfect seal between the outer body of the seal and the wheel hub on the one hand and between the inner body of the seal and the axle spindle on the other hand, is commonly destroyed or lost when the seal is pried out of position. Thus, it is customary in practice to replace the seal each time a wheel is removed.
There has been some effort to design axle seals which may be reused, and one such reusable seal is shown in Matsushima, U.S. Pat. No. 3,682,488 issued Aug. 8, 1972. However, the Matsushima seal has metal-to-metal contact between the seal and the axle spindle, thus requiring the seal to have a very close fluid-tight, metal-to-metal fit on the spindle. Obviously, any irregularity on the spindle surface or any damage to the inner seal shell would prevent its reuse.